Good day everyone.

I bought this rifle from a recent gun show. According to the previous owner this is a rifle he put together himself. It's built on a Mk2 receiver, and the barrel is made by the same company that made the L42 barrels. I'm not totally sold on the bi-pod, and I might end up changing the stock, and the scope mount. But that'll be for another day. The issue I'm having is the magazine sits too low for rounds to get fed into the chamber. I tried my other 7.62 mag but that one doesn't work ether. Where exactly does material need to be removed on the bottom of the receiver? If anyone has a blueprint, or pictures it would be greatly appreciated. Feel free to ask for any other pictures, or if you have any questions. Cheers!     

I'll bet its the stock being too "fat".

The mag catch is in the bottom metal a "fat" stock latches lower down unless adjusted.

Try removing the forend & reassembling without the wood, but with the spacer.

If it fixes the problem you need to do some bottom wood relieving inside the recess for the metal to raise it.

K-Z: In regards to removing metal from the recievers mag well area. The supplied photo shows the areas circled in red that need to be opened up slightly but not by much. The other addition is to very slightly work the magazine where it mates to the magazine well with a small plastic mallet or a piece of hardwood. Make certain that the magazine positively engages the magazine catch. Using a Dremel Tool with small grinding stones make quick work of the affected areas...

Shamu, thank you for the suggestion.

Unfortunately the mag is still too low to catch rounds even with the forend off.

Perfect! Thank you kindly, this is exactly what I was looking for.

Goosic, thank you for the info and the pictures.

Ball park how much metal would you say you removed? Ten thousands (0.010")? The picture that Britishrifles shared says to remove .075" which seems like WAY too much to me. Also, was bending the ejector tab on the mag necessary for it to function? I would've thought it's fine where it is. Not trying to say you're wrong, I'm just curious. 

This!

Sneak up on it Measure twice file once!

Rule 2 "Modify the cheapest part first".

Bending the ejector tab was part of tapping the back of the magazine down to effectively bring the back of the magazine up to get the bullets to feed without having to remove any more metal in the mag well than necessary. While I do appreciate all the information I have accumulated from Mr. Laidler, I have also found simpler ways to go about modifying the No4 with zero issues...